void main(){
  import std.stdio, std.string, std.conv, std.algorithm;

  int n, m, s, g; rd(n, m, s, g);
  auto d=new int[][](n, n);
  const inf=1_000_000_000;
  foreach(i; 0..n) fill(d[i], inf), d[i][i]=0;
  auto es=new int[][](n, n);
  foreach(i; 0..m){
    int a, b, c; rd(a, b, c);
    d[a][b]=d[b][a]=c;
    es[a][b]=es[b][a]=c;
  }

  foreach(_; 0..n)foreach(i; 0..n)foreach(j; 0..n){
    d[i][j]=min(d[i][j], d[i][_]+d[_][j]);
  }
  auto mn=d[s][g], r=new int[](0);
  for(auto cur=s; cur!=g; ){
    r~=cur;
    foreach(nex; 0..n){
      if(es[cur][nex] && d[cur][g]==d[nex][g]+es[cur][nex]){
        cur=nex;
        break;
      }
    }
  }
  r~=g;
  writefln("%(%d %)", r);
}

void rd(T...)(ref T x){
  import std.stdio, std.string, std.conv;
  auto l=readln.split;
  assert(l.length==x.length);
  foreach(i, ref e; x){
    e=l[i].to!(typeof(e));
  }
}